1. Field of the Invention
This invention is for pyrotechnic compositions for colored smoke production.
2. Description of Related Art
Pyrotechnic compositions for colored smoke production utilize the atomization of a dye by the use of a high energy pyrotechnic explosive, or by volatilization of a dye by the heat produced during the burning of a pyrotechnic composition. A conventional pyrotechnic composition for colored smoke production includes a dye mixed with a heat producing composition. The heat-producing composition is typically a fuel-oxidizer combination such as sulfur-potassium chlorate or sucrose-potassium chlorate. The fuel-oxidizer combination normally contains a small amount of coolant, such as sodium bicarbonate.
Other pyrotechnic compositions for producing colored smoke have been made by incorporating an iodine-base oxidizer with a suitable fuel, so that upon combustion or detonation of the composition, either iodine or colored metallic iodides, or both, are formed and dispersed by the heat of the reaction.
These pyrotechnic compositions are generally dry mixed and pressed into a cannister to provide a coherent shape.
Instability and discontinuity of the final formulation have been avoided by utilizing inert polymeric binders to yield a castable system. Polymer-bonded smoke compositions offer numerous advantages, such as improved mechanical properties and safety in handling, over conventional pressed smoke mixtures. However, the amount of liquid binder required is excessive when large amounts of finely-divided pigment are required. Accordingly, to achieve a castable composition, the organic pigment-pyrotechnic mixture is usually so diluted with inert binder that the smoke generating capability of the charge is unacceptably reduced.